In the past, electrosurgical devices had an active electrode that was used for performing cutting and coagulation, and a return electrode which usually comprised an adhesive for attachment to a patient's skin. When the electrosurgery unit surgery pencil was activated, the RF energy circulated from the active electrode to the return electrode through the patient's body with the distances between the active and return electrodes being fairly significant.
This prior art system presents several deficiencies and creates, a number of problems that can be dangerous for the patient. First, because of the significant distance between the active and return electrodes, high voltages at high frequencies are transversed through the body in order to close the circuit between the active and return electrodes. These high voltages and frequencies can be very dangerous to the patient. Second, due to the fact that the body has an electrical resistance, the cutting and coagulation affects are significantly diminished as the distance between the active and return electrodes is increased. Accordingly, high power from the ESU is needed in order to obtain effective cutting and coagulation performance. Again, the high power required from the ESU can be dangerous to the patient.
Third, in many cases, patients have incurred significant burns because of poor contact between the return electrode and the patient's skin. Finally, dangerous capacitive coupling has occurred in laparoscopic surgery which has resulted in dangerous burns to the patient. These burns could not be detected because they are out of the field of view of the laparoscope thereby putting the patient's life in danger.
A bipolar function for open and laparoscopic procedures is presently being used with the bipolar suction of the ESU. However, this system and the related instruments are used only to stop bleeding within a patient and is not capable of performing a cutting operation.
As previously stated in the section referred to as “related application”, the present invention is related to the same inventor's pending patent application entitled “Telescopic Surgical Device and Method Therefor”. The similarities between the telescopic pencil described in the pending application and the present invention described in this application is that both inventions refer to a telescopic pencil which can have multifunctional applications. The main difference between the inventions is that the pending telescopic pencil patent application refers to a monopolar pencil only which has only one contact for the electrode while the ESU pencil of the present invention described in this application can be used as a monopolar instrument, a monopolar/bipolar instrument or a bipolar instrument. The ESU pencil of the present invention has an electrode which comprises two contacts, one which is used as an active electrode and another which is used as a return electrode when the instrument is used as a bipolar functioning instrument for a monopolar/bipolar functioning instrument. Alternatively, when the instrument is only used as a monopolar functioning instruments a separate electrode is applied to a different part of the patient's body, usually on the patient's leg. This separate electrode functions as the return electrode.